Is this the first mayor scala release that doesn't introduce a huge language or library change?
Transitioning to 2.11 should be smooth, aside from some library deprecations not much has changed.
2.11 set the tone for the remainder of the 2.x cycle: smaller, faster, stabler. 2.12 will focus on Java 8 support and making it (even) easier to learn and use Scala.
We're also working on making the compiler a better platform for others to innovate on -- originally via compiler plugins, now using reflection & macros. A lot of cool stuff is happening outside core Scala, such as scala.js, and we hope to spur on that trend.
(I'm the Scala Tech Lead at Typesafe.)
Part of the solution will be tooling, and the team at EPFL has started prototyping a migration tool that generates patches to turn a well-typed Scala 2 program into the equivalent one on Scala 3. I believe our type system and the fact that we're a compiled language will make a big difference compared to Python.
Naturally, tradeoffs will be made, are you guys at a point yet where you can reveal what we're going to _lose_ in terms of functionality and flexability?
I know the core Scalaz developers had a bit of an uproar on Twitter when Dotty was first revealed (due to the simplified/less powerful type system in Dotty that may make some scalaz magic very difficult to pull off).
Otherwise, improved tooling, build times, Scala 2 sans les warts, etc. will be a boon for the language.
So, Scala 3.0-M1 in 2016? Give us the inside word ;-)